<!DOCTYPE html>
<html lang="zh">
<head>
    <meta charset="UTF-8">
    <title>响应式布局基础</title>
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <link rel="stylesheet" href="css/normalize.css">
    <link rel="stylesheet" href="css/layout4.css">
</head>
<body>
<div class="wrapper">
    <div class="header">
        <h1>响应式设计</h1>
    </div>
    <div class="main">
        <div class="sidebar">
            <p>侧边栏</p>
        </div>
        <div class="content">
            <p>内容区域</p>
        </div>
    </div>
    <div class="footer">
        <address>页脚</address>
    </div>
</div>
</body>
</html>